This invention relates to a filter bag, and more particularly to a vacuum cleaner filter bag having a removable air impervious dust receptacle.
Upright vacuum cleaners conventionally employ debris collecting bags formed of an air pervious or filter material. In such cleaners, an elongated generally tubular bag is disposed in vertical axial alignment with the operating handle of the cleaner. Means are provided for coupling the bag to the cleaner, whereby a debris entrained air stream is introduced into the bag so that separation of the debris from the air stream is accomplished. Means are further provided for removal of the collected debris within the bag at suitable intervals.
In the type filter bag to which this invention is particularly directed, a feed tube running parallel with the bag body is employed. The lower end of such feed tube is provided with suitable coupling means to permit it to be attached to an outlet port of a motor operated suction fan of the cleaner. The upper end of the tube is attached to the corresponding upper end of the bag and provision is made for passage of the air stream from the tube into the upper end of the filter bag. The debris is picked up by the inlet nozzle of the suction fan and carried by the air stream produced thereby to the upper end of the bag by means of the feed tube, whence it is introduced into the filter bag and the separated debris ultimately falls into and is collected at the bottom of the bag. Removal of the debris is accomplished by means of a sealable access opening located at the bottom of the bag. A bag of this general type is shown and described in the patent to S. Howard, et al., entitled "Vaccum Cleaner Bag", U.S. Pat. No. 3,619,989, issued Nov. 16, l971.
In bags of this type, in order to permit the internal pressure in the bag to be relieved and to provide for a continuous air stream, it has been necessary to utilize relatively expensive air pervious filtering materials in order to accomplish the necessary separation of the debris from the air stream in which it is entrained. Customarily, such bags are formed of fabric or textile materials permitting the reuse of the bag. Alternatively, the bag may be formed of paper having the necessary filtration characteristics. The latter form of paper filtration bag is disposable. In either event, the bag material represents considerable expense and in many instances is inconvenient to manipulate and empty for reuse.